ΔE 17.3, loose: different enough that you should pick on purpose. Brassy Brass is a little lighter, much more muted, warmer than Tourmaline Alchemy.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Brassy Brass is a little lighter, much more muted, warmer than Tourmaline Alchemy.
The same difference applies the other way round: Tourmaline Alchemy is a little darker, much more saturated, cooler.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Tourmaline Alchemy on the colour wheel See Brassy Brass on the colour wheel
All matches: Tourmaline Alchemy equivalents · Brassy Brass equivalents